presentation of 5_weeks_summer_training_,dept
TRANSCRIPT
Presentation of 5 weeks summer training ,Dept of civil
engineering ,lovely professional university .
Student detail
• Name : Hari Bhakta Sharma.• Course: B-tech(hons),civil
engineering• Year/sem:3rd /6th
Name of project
• Four lanning of NH75E including the section from KM 82+400 to KM 195+800
• APPROX 112+200 KM on Sidhi-singruali section • State : Madhya pradesh
More on project holders • Authority : Madhya Pradesh road development
corporation limited .• Concessionaire : sidhi-singurali road project
limited• PMC: Bloom infra and logistic India limited.• Independent engineers: MC Consulting
engineers.• EPC Contractors: Gammon infra project limited.• Contractor: techno unique infrastructural Pvt
limited.
What is there in this presentation.
• Need of highway construction.• Planning surveys.• Earthworks.• Different section of crust with different test for
material used on it.• Difficulties face in this project and the
solution.• Learning outcome.
Planning surveys
• Highway planning phases includes 1) Assessment of road length requirement for
an area. 2) preparation of master plan showing the
phasing of plan .
Planning survey consists of following studies
Economics studies
Financial studies
Traffic or road use studies
Engineering studies
STEPS IN PROJECTS WORK• Map study• Reconnaissance• Preliminary survey• Location of final alignment• Detailed survey• Material survey• Design• Earth work• Pavement construction• Construction controls
EARTH WORK
• Earthwork are engineering works created through the moving or processing of parts of the earth’s surface involving quantities of soil or unformed rock. The earth may be moved to another location and formed into a desired shape for a purpose.
• Equipment used for earth work are listed few below:1. Power shovel2. dragline3. Clamshell 4. Bulldozer5. Digger6. Hoe etc
EMBANKMENT
• The need for raising the grade line of the highway above the existing ground level attributes to the need for the construction of embankments. The reason for raising the grade line of highway may be summed as below:
• To keep the subgrade above the ground water table.• To prevent the damages by the surface and capillary
water to the pavements.• To maintain the design standards of the highway
with respect to the vertical alignment.
FEW MORE POINTS
• The IRC 36 deals with the recommended practice for construction of earth embankments for roads works.
• The embankment should be constructed upto the height of 200mm above maximum rainfall level.
• No bio degradable material should be left in the soil, decomposition after which may lead to the settlement of the soil which it occupies.
• Safe side slope shall range from 1 ½ :1 to 2:1.• The OGL shall be brought to the not less than 95% MDD.• To compaction of the embankment shall be constructed in
layers. The embankment layers shall be deposited in layers not exceeding 25cm in loose thickness.
SUBGRADE
• subgrade should posses sufficient stabiThe subgrade soil and its properties are important in design of pavement structure.
• The main function of the subgrade is to give adequate support to the pavement and for this the lity under adverse climate and loading conditions.
• The formation of waves , corrugation , rutting and shoving in black top pavement and the phenomena of pumping, blowing and consequent cracking of cement concrete pavement are generally attributed due to the poor subgrade conditions
PREPARATION OF SUBGRADE• The preparation of subgrade includes all the operation before the pavement
structure could be laid over it and compacted. The preparation of subgrade would include site clearance, grading and compaction.
• The subgrade may be situated on embankment or excavation or at the existing ground surface. In all the case the site should be cleared off and the top soil consisting of grass, root rubbish and other organic matter are to be removed.
IMPORTANTS POINTS
• The height of the subgrade should be 500mm.• 500mm in prepared in a layer, after compacting each
layers.• Maximum depth of each layer after compaction should be
200mm.• The subgrade is constructed in a layer because the
compaction by vibrator is not able to compact beyond certain limit.
• Subgrade should attain 97% of MDD.• The RMM helps to check the moisture content which gives
MDD we desire to attain.
DETERMING ROLLING PATTERN
• The number of passes that will help us have MDD is found out by setting up a test lane of about 150m which is a replica of actual soil condition.
• Soil is laid in its natural condition and roller is passed over it.
• At regular interval the percentage compaction is found by the sand replacement method.
• The graph is plotted between percentage compaction and number of passes .
continue• After some point of passes at equivalent moisture content the graph
start to travel parallel to x- axis( i.e. no of passes) the point when graph start to behave so will give the equivalent number of much needed rolling passes that the site supervisor can monitor without much scientific input .
• To find the percentage compaction by sand replacement method , number of test pit is dug in the test lane ,this test pit is filled by the sand and the rolling is started.
• After each pass the sand is replaced and the compacted sand is subjected to the investigation ,where we ought to find out the MDD
• Y= Yw/1+w helps us to find the maximum dry density
• Where Y is dry density and Yw bulk density and w id moisture content.
• Yw is found out by formula Yw = M/V.
GRANULAR SUBASE LAYER (GSBL)
• The aggregate base layers serve a variety of purposes, including reducing the stress applied to the subgrade layer and providing drainage for the pavement structure.
• Granular bases are typically constructed by spreading the materials in thin layers of 150 mm (6 in) to 200 mm (8 in) and compacting each layer by rolling over it with heavy compaction equipment.
• Granular base materials typically contain a crushed stone content in excess of 50 percent of the coarse aggregate particles also aggregates used should not less be than 20mm.
WMM ( WET MIX MACADAM)
• Unlike WBM aggregates used are of the smaller sizes, varies between the 4.75 mm to 20 mm sizes and the binders are premixed in a batching plant or in a mixing machine.
Comparison of the WBM and WMM
• The WMM roads are said to be more durable.• The WMM roads gets dry sooner and can be opened for traffic
withing less time as compare to the WBM roads which take about one month for getting dry.
• WMM roads are soon ready to be black topped with the Bituminous layers.
• WMM roads are constructed at the faster rate.• The consumption of the water is less in case of the WMM
roads.• Stone aggregates used in WBM is larger in size which varies
from 90 mm to 20 mm depending upon the grade but in case of the WMM size varies from 4.75 mm to 20 mm.